The present invention relates to an automatic transmission provided with the overdrive device of the type in which an a torque converter, an aoutomatic transmission and a final reduction gear are integrally assembled.
In a conventional automatic transmission with an overdrive device, a planetary gear device is used for increasing the rotation speed of the output of the transmission. Particularly, in the three-speed change gear transmission, the power transmission flow is arranged on an axis. Because of such an arrangement, a pair of planetary gear devices must be provided, which further requires to provide at least two transmitting devices comprising a clutch, band and one-way clutch. Such a construction makes the appratus large and complicated, which also causes complication of the hydraulic control system.